Semiconductor module and semiconductor device

ABSTRACT

The present invention is intended to provide a semiconductor module and a semiconductor device that are compatible with various rated currents. A semiconductor module includes a lead frame, and a semiconductor element joined with the lead frame. The lead frame includes a first joining structure and a second joining structure. The first joining structure includes a void part as a part at which the lead frame does not exist, and the second joining structure includes a void part as a part at which the lead frame does not exist. Each of the first joining structure and the second joining structure has a shape such that one of the first joining structure and the second joining structure complements at least part of the void part of the other assuming that the first joining structure and the second joining structure are overlapped.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.16/340,156 filed Apr. 8, 2019, which is the U.S. National Stage ofInternational Application No. PCT/JP2016/083045 filed Nov. 8, 2016, theentire content of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a semiconductor module and asemiconductor device.

BACKGROUND ART

A semiconductor module in which a semiconductor element as a switchingelement is joined on a lead frame and controlled to turn on and off toconvert electrical power has been known (refer to Patent Document 1, forexample).

When conventional semiconductor modules having different rated currentsare to be manufactured, it is necessary to design a member such as thelead frame dedicated for each semiconductor module. Since dedicatedmembers has to be designed for each of different rated currents, therehave been problems such as an increase in development cost andmanufacturing cost and an increase in the development period. The ratedcurrent is a current value determined in accordance with thespecifications of each semiconductor module.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: WO 2011/155165

SUMMARY Problem to be Solved by the Invention

As described above, the conventional semiconductor module requiresdedicated design of members for each of different rated currents, andthus the members cannot be standardized, resulting in problems such asan increase in development cost and manufacturing cost, and an increasein the development period. In addition, there is a problem ofcomplication of the process of manufacturing semiconductor moduleshaving a plurality of rated currents.

The present invention has been made to solve the above-describedproblems, and it is an object of the present invention to provide asemiconductor module and a semiconductor device that are compatible withvarious rated currents.

Means to Solve the Problem

A semiconductor module according to the present invention includes: alead frame; and a semiconductor element joined with the lead frame. Thelead frame includes a first joining structure and a second joiningstructure. The first joining structure is disposed on a first side ofthe lead frame, and the second joining structure is disposed on a secondside of the lead frame facing to the first side. The first joiningstructure includes a void part as a part at which the lead frame doesnot exist, and the second joining structure includes a void part as apart at which the lead frame does not exist. Each of the first joiningstructure and the second joining structure has a shape such that one ofthe first joining structure and the second joining structure complementsat least part of the void part of the other assuming that the firstjoining structure and the second joining structure are overlapped.

Effects of the Invention

A semiconductor module according to the present invention includes afirst joining structure and a second joining structure, and thus anoptional number of semiconductor modules can be coupled with each otherin line. Specifically, the plurality of semiconductor modules can beconnected in parallel with each other, and thus the rated current valueof the plurality of coupled semiconductor modules as a whole can bechanged in accordance with the number of the coupled semiconductormodules. Accordingly, semiconductor modules are not needed to beexclusively designed for each of different rated current values, andthus can be commonly used. As a result, development cost andmanufacturing cost can be reduced. In addition, the manufacturingprocess can be simplified.

These and other objects, features, aspects and advantages of the presentinvention will become more apparent from the following detaileddescription of the present invention in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a semiconductor module according to afirst embodiment.

FIG. 2 is a cross-sectional view of the semiconductor module accordingto the first embodiment.

FIG. 3 is a perspective view of a semiconductor device according to thefirst embodiment.

FIG. 4 is a cross-sectional view of the semiconductor device accordingto the first embodiment.

FIG. 5 is a cross-sectional view of a semiconductor module according toa modification of the first embodiment.

FIG. 6 is a cross-sectional view of the semiconductor device accordingto the modification of the first embodiment.

FIG. 7 is a perspective view of a semiconductor module according to asecond embodiment.

FIG. 8 is a cross-sectional view of the semiconductor module accordingto the second embodiment.

FIG. 9 is a perspective view of a semiconductor device according to thesecond embodiment.

FIG. 10 is a cross-sectional view of the semiconductor device accordingto the second embodiment.

FIG. 11 is a perspective view of a semiconductor module according to athird embodiment.

FIG. 12 is a cross-sectional view of the semiconductor module accordingto the third embodiment.

FIG. 13 is a perspective view of a semiconductor device according to thethird embodiment.

FIG. 14 is a cross-sectional view of the semiconductor device accordingto the third embodiment.

FIG. 15 is a perspective view of a semiconductor module according to afourth embodiment.

FIG. 16 is a cross-sectional view of the semiconductor module accordingto the fourth embodiment.

FIG. 17 is a perspective view of a semiconductor device according to thefourth embodiment.

FIG. 18 is a cross-sectional view of the semiconductor device accordingto the fourth embodiment.

FIG. 19 is a perspective view of a semiconductor module according to afifth embodiment.

FIG. 20 is a cross-sectional view of the semiconductor module accordingto the fifth embodiment.

FIG. 21 is a perspective view of a semiconductor module according to amodification of the fifth embodiment.

FIG. 22 is a cross-sectional view of the semiconductor module accordingto the modification of the fifth embodiment.

FIG. 23 is a perspective view of a semiconductor module according to asixth embodiment.

FIG. 24 is a perspective view of a semiconductor module according to amodification of the sixth embodiment.

FIG. 25 is a perspective view of a semiconductor module according to aseventh embodiment.

FIG. 26 is a cross-sectional view of the semiconductor module accordingto the seventh embodiment.

FIG. 27 is a perspective view of a semiconductor module according to amodification of the seventh embodiment.

FIG. 28 is a perspective view of a semiconductor device according to aneighth embodiment.

FIG. 29 is a perspective view of an inside of the semiconductor deviceaccording to the eighth embodiment.

DESCRIPTION OF EMBODIMENTS First Embodiment

FIG. 1 is a perspective view of a semiconductor module 100 according toa first embodiment. FIG. 2 is a cross-sectional view of thesemiconductor module 100 taken along line A1-A1 in FIG. 1 . Asillustrated in FIGS. 1 and 2 , the semiconductor module 100 includes alead frame 3 and a semiconductor element 1 joined with the lead frame 3.

The semiconductor element 1 is joined with the lead frame 3 by solder 2,for example. The semiconductor element 1 is a power semiconductorelement. The semiconductor element 1 is a switching element such as aninsulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductorfield-effect transistor (MOSFET). The semiconductor element 1 may be afree wheel diode. The semiconductor element 1 may contain a wide-bandgapsemiconductor such as SiC, GaN, or diamond.

Upper and lower surfaces (which are surfaces on the +z direction sideand the -z direction side) of the semiconductor element 1 are eachprovided with a main electrode. In addition, a control electrode isprovided, for example, on part of the upper surface of the semiconductorelement 1.

The conductive lead frame 3 is formed of, for example, copper oraluminum. The lead frame 3 may be made of an alloy containing copper oraluminum as a main component. As illustrated in FIGS. 1 and 2 , a sideon the +x direction side of the lead frame 3 is defined as a first sideS1. A side on the -x direction side of the lead frame 3 is defined as asecond side S2. The first side S1 and the second side S2 face to eachother.

The lead frame 3 includes a first joining structure 11 and a secondjoining structure 12. The first joining structure 11 is disposed on thefirst side S1 of the lead frame 3. The second joining structure 12 isdisposed on a second side S2 of the lead frame 3. The first joiningstructure 11 includes a substantial part 11 a at which the lead frame 3exists and a void part 11 b in which the lead frame 3 does not exist.The second joining structure 12 includes a substantial part 12 a atwhich the lead frame 3 exists and a void part 12 b at which the leadframe 3 does not exist.

Assuming that the first joining structure 11 and the second joiningstructure 12 are overlapped, each of the first joining structure 11 andthe second joining structure 12 has a shape such that one of the firstjoining structure 11 and the second joining structure 12 complements atleast part of the void part 11 b or 12 b of the other. In other words,in FIG. 2 , assuming that the second joining structure 12 is moved inparallel in the x direction and overlapped with the first joiningstructure 11, the substantial part 11 a of the first joining structure11 complements the void part 12 b of the second joining structure 12,and the substantial part 12 a of the second joining structure 12complements the void part 11 b of the first joining structure 11.

The semiconductor module 100 may further include an insulating member 4as described in a fifth embodiment. The semiconductor module 100 mayfurther include a cooler 5 as described in a modification of the fifthembodiment. An electrode terminal 6 may be further provided as describedin a sixth embodiment. Further, as described in a seventh embodiment, aheat pipe may be incorporated in the lead frame 3. In addition, asdescribed in an eighth embodiment, a sealing resin 15 may be providedfor sealing.

FIG. 3 is a perspective view of a semiconductor device 110 according tothe first embodiment. FIG. 4 is a cross-sectional view of thesemiconductor device 110 taken along line A2-A2 in FIG. 3 . Asillustrated in FIGS. 3 and 4 , the semiconductor device 110 has aconfiguration in which two semiconductor modules 100 are coupled witheach other. For the sake of description, the two semiconductor modules100 are referred to as semiconductor modules 100A and 100B,respectively, for distinction.

As illustrated in FIGS. 3 and 4 , among the semiconductor modules 100Aand 100B adjacent to each other, the first side S1 of the semiconductormodule 100B and the second side S2 of the semiconductor module 100A faceto each other. The first joining structure 11 of the semiconductormodule 100B and the second joining structure 12 of the semiconductormodule 100A are electrically joined with each other by solder 10.

As illustrated in FIGS. 3 and 4 , the semiconductor elements 1 can beconnected in parallel with each other by electrically joining the leadframes 3 of the semiconductor modules 100A and 100B to each other. Thus,the rated current value of the semiconductor device 110 can be changedin accordance with the number of the coupled semiconductor modules 100.

The number of semiconductor modules 100 provided in the semiconductordevice 110 is not limited to two. An optional number of semiconductormodules 100 can be coupled with each other in the +x direction and -xdirection in accordance with the rated current of the semiconductordevice 110.

Effects

The semiconductor module 100 according to the first embodiment includesthe lead frame 3 and the semiconductor element 1 joined with the leadframe 3. The lead frame 3 includes the first joining structure 11 andthe second joining structure 12. The first joining structure 11 isdisposed on the first side Si of the lead frame 3, and the secondjoining structure 12 is disposed on the second side S2 of the lead frame3 facing to the first side S1. The first joining structure 11 includesthe void part 11 b as a part at which the lead frame 3 does not exist,and the second joining structure 12 includes the void part 12 b as apart at which the lead frame 3 does not exist. Each of the first joiningstructure 11 and the second joining structure 12 has a shape such thatone of the first joining structure 11 and the second joining structure12 complements at least part of the void part 11 b or 12 b of the otherassuming that the first joining structure 11 and the second joiningstructure 12 are overlapped.

Since the semiconductor module 100 according to the first embodimentincludes the first joining structure 11 and the second joining structure12, an optional number of semiconductor modules 100 can be coupled witheach other in line. Accordingly, since a plurality of semiconductormodules 100 can be connected in parallel with each other, the ratedcurrent value of a plurality of coupled semiconductor modules 100 as awhole can be changed in accordance with the number of coupledsemiconductor modules 100. In this manner, according to the firstembodiment, it is possible to obtain the semiconductor module 100 withwhich the rated current value of a plurality of coupled semiconductormodules 100 as a whole can be changed in accordance with the number ofcoupled semiconductor modules 100. Thus, the semiconductor modules 100do not need to be exclusively designed for each of different ratedcurrent values and can be commonly used. As a result, development costand manufacturing cost can be reduced. In addition, the manufacturingprocess can be simplified.

Moreover, in the semiconductor module 100 according to the firstembodiment, the lead frame 3 contains copper or aluminum. Accordingly,it is possible to improve the thermal conduction efficiency of the leadframe 3.

The semiconductor device 110 according to the first embodiment includesa plurality of semiconductor modules 100. Among the plurality ofsemiconductor modules 100, the first side S1 of one of the semiconductormodules 100 adjacent to each other is disposed facing to the second sideS2 of the other of the semiconductor modules 100 adjacent to each other.The first joining structure 11 of one of the semiconductor modules 100adjacent to each other is electrically joined with the second joiningstructure 12 of the other of the semiconductor modules 100 adjacent toeach other.

Accordingly, the rated current value of the semiconductor device 110 canbe changed by changing the number of coupled semiconductor modules 100,and thus it is not necessary to design the lead frame 3 having adedicated shape for each of different rated current values, and thesemiconductor module 100 can be manufactured at low cost. In addition,the semiconductor device 110 is manufactured by coupling a plurality ofsemiconductor modules 100 having the same structure, and thussemiconductor devices 110 having various rated current values can beeasily manufactured.

In the semiconductor device 110 according to the first embodiment, thefirst joining structure 11 of one of the semiconductor modules 100adjacent to each other and the second joining structure 12 of the otherof the semiconductor modules 100 adjacent to each other are electricallyjoined with each other by soldering.

Accordingly, since the first joining structure 11 and the second joiningstructure 12 of the semiconductor modules 100 adjacent to each other aresoldered with each other, excellent current conduction and strong jointcan be achieved.

Modification of First Embodiment

FIG. 5 is a cross-sectional view of a semiconductor module 101 accordingto a modification of the first embodiment. FIG. 6 is a cross-sectionalview of a semiconductor device 111 according to the modification of thefirst embodiment. As illustrated in FIG. 5 , the second joiningstructure 12 of the semiconductor module 101 includes a void part 12 cthat is not used for joining. In other words, as illustrated in FIG. 6 ,the void part 12 c that is not used for joining is not complemented bythe substantial part of the first joining structure 11.

Second Embodiment

FIG. 7 is a perspective view of a semiconductor module 200 according toa second embodiment. FIG. 8 is a cross-sectional view of thesemiconductor module 200 taken along line B1-B1 in FIG. 7 . Thesemiconductor module 200 has the same configuration as that of thesemiconductor module 100 (FIGS. 1 and 2 ) except for the shapes of thefirst joining structure 21 and the second joining structure 22.

The lead frame 3 of the semiconductor module 200 includes the firstjoining structure 21 and the second joining structure 22. The firstjoining structure 21 is disposed on the first side 51 of the lead frame3. The second joining structure 22 is disposed on the second side S2 ofthe lead frame 3. The first joining structure 21 includes a substantialpart 21 a at which the lead frame 3 exists and a void part 21 b at whichthe lead frame 3 does not exist. The second joining structure 22includes a substantial part 22 a at which the lead frame 3 exists and avoid part 22 b at which the lead frame 3 does not exist.

In addition, the first joining structure 21 includes a through-hole 21 cat the substantial part 21 a. The second joining structure 22 includes ahole 22 c at the substantial part 22 a. A female screw is formed insidethe hole 22 c.

Each of the first joining structure 21 and the second joining structure22 has a shape such that one of the first joining structure 21 and thesecond joining structure 22 complements at least part of the void part21 b or 22 b of the other assuming that the first joining structure 21and the second joining structure 22 are overlapped. In other words, inFIG. 8 , assuming that the second joining structure 22 is moved inparallel in the x direction and overlapped with the first joiningstructure 21, the substantial part 21 a of the first joining structure21 complements the void part 22 b of the second joining structure 22,and the substantial part 22 a of the second joining structure 22complements the void part 21 b of the first joining structure 21.

In FIG. 8 , assuming that the second joining structure 22 is moved inparallel in the x direction and overlapped with the first joiningstructure 21, the through-hole 21 c of the first joining structure 21and the hole 22 c of the second joining structure 22 are disposed inline.

FIG. 9 is a perspective view of a semiconductor device 210 according tothe second embodiment. FIG. 10 is a cross-sectional view of thesemiconductor device 210 taken along line B2-B2 in FIG. 9 . Asillustrated in FIGS. 9 and 10 , the semiconductor device 210 has aconfiguration in which two semiconductor modules 200 are coupled witheach other. For the sake of description, the two semiconductor modules200 are referred to as semiconductor modules 200A and 200B,respectively, for distinction.

As illustrated in FIGS. 9 and 10 , among the semiconductor modules 200Aand 200B adjacent to each other, the first side S1 of the semiconductormodule 200B is disposed facing to the second side S2 of thesemiconductor module 200A. The first joining structure 21 of thesemiconductor module 200B is electrically joined with the second joiningstructure 22 of the semiconductor module 200A by screwing.

Accordingly, the through-hole 21 c provided in the first joiningstructure 21 of the semiconductor module 200B and the hole 22 c providedin the second joining structure 22 of the semiconductor module 200A arescrewed with each other by a screw 20.

As illustrated in FIGS. 9 and 10 , the semiconductor elements 1 can beconnected in parallel with each other by electrically joining the leadframes 3 of the semiconductor modules 200A and 200B. Accordingly, therated current value of the semiconductor device 210 can be changed inaccordance with the number of the coupled semiconductor modules 200.

The number of semiconductor modules 200 provided in the semiconductordevice 210 is not limited to two. An optional number of semiconductormodules 200 can be coupled with each other in the +x direction and −xdirection in accordance with the rated current of the semiconductordevice 210.

In the semiconductor module 200, no female screw may be formed insidethe hole 22 c provided in the second joining structure 22, but the hole22 c may be used as a through-hole. In this case, in the semiconductordevice 210, the through-hole 21 c provided in the first joiningstructure 21 and the hole 22 c provided in the second joining structure22 are screwed with a bolt and a nut.

Effects

In the semiconductor module 200 according to the second embodiment, thefirst joining structure 21 includes the through-hole 21 c and the secondjoining structure 22 includes the hole 22 c. Assuming that the firstjoining structure 21 and the second joining structure 22 are overlapped,the through-hole 21 c and the hole 22 c are disposed in line.

Accordingly, the through-hole 21 c of the first joining structure 21 ofone of the semiconductor modules 200, can be joined with the hole 22 cof the second joining structure 22 of the other semiconductor module 200adjacent thereto through a rod-shaped member such as a screw.

In the semiconductor device 210 according to the second embodiment, thefirst joining structure 21 of one of the semiconductor modules 200adjacent to each other and the second joining structure 22 of the otherof the semiconductor modules 200 adjacent to each other are screwed andelectrically joined with each other.

The first joining structure 21 and the second joining structure 22 ofthe semiconductor modules 200 adjacent to each other can be easilyjoined with each other by screwing.

Third Embodiment

FIG. 11 is a perspective view of a semiconductor module 300 according toa third embodiment. FIG. 12 is a cross-sectional view of thesemiconductor module 300 taken along line C1-C1 in FIG. 11 . Thesemiconductor module 300 has the same configuration as that of thesemiconductor module 100 (FIGS. 1 and 2 ) except for the shapes of afirst joining structure 31 and a second joining structure 32.

The lead frame 3 of the semiconductor module 300 includes the firstjoining structure 31 and the second joining structure 32. The firstjoining structure 31 is disposed on the first side S1 of the lead frame3. The second joining structure 32 is disposed on the second side S2 ofthe lead frame 3. The first joining structure 31 includes a substantialpart 31 a at which the lead frame 3 exists and a void part 31 b at whichthe lead frame 3 does not exist. The second joining structure 32includes a substantial part 32 a at which the lead frame 3 exists and avoid part 32 b at which the lead frame 3 does not exist.

In the third embodiment, the first joining structure 31 includes a malejoint. The second joining structure 32 includes a female joint. Asillustrated in FIGS. 11 and 12 , each joint is an ant-shaped joint, forexample. The ant-shaped joint is also called a dovetail joint.

Each of the first joining structure 31 and the second joining structure32 has a shape such that one of the first joining structure 31 and thesecond joining structure 32 complements at least part of the void part31 b or 32 b of the other assuming that the first joining structure 31and the second joining structure 32 are overlapped. In other words, inFIG. 12 , assuming that the second joining structure 32 is moved inparallel in the x direction and overlapped with the first joiningstructure 31, the substantial part 31 a of the first joining structure31 complements the void part 32 b of the second joining structure 32,and the substantial part 32 a of the second joining structure 32complements the void part 31 b of the first joining structure 31.

In the third embodiment, assuming that the second joining structure 32is moved in parallel in the x direction and overlapped with the firstjoining structure 31, the male joint of the first joining structure 31and the female joint of the second joining structure 32 are fitted toeach other.

FIG. 13 is a perspective view of a semiconductor device 310 according tothe third embodiment. FIG. 14 is a cross-sectional view of thesemiconductor device 310 taken along line C2-C2 in FIG. 13 . Asillustrated in FIGS. 13 and 14 , the semiconductor device 310 has aconfiguration in which two semiconductor modules 300 are coupled witheach other. For the sake of description, the two semiconductor modules300 are referred to as semiconductor modules 300A and 300B,respectively, for distinction.

As illustrated in FIGS. 13 and 14 , among the semiconductor modules 300Aand 300B adjacent to each other, the first side Si of the semiconductormodule 300B is disposed facing to the second side S2 of thesemiconductor module 300A. The first joining structure 31 of thesemiconductor module 300B and the second joining structure 32 of thesemiconductor module 300A are electrically joined with each other byfitting.

In other words, the male joint provided in the first joining structure31 of the semiconductor module 300B and the female joint provided in thesecond joining structure 32 of the semiconductor module 300A are fittedwith each other. The semiconductor module 300B is slid in the ydirection with respect to the semiconductor module 300A to fit the malejoint and the female joint to each other.

As illustrated in FIGS. 13 and 14 , the semiconductor elements 1 can beconnected in parallel with each other by electrically joining the leadframes 3 of the semiconductor modules 300A and 300B with each other.Accordingly, the rated current value of the semiconductor device 310 canbe changed in accordance with the number of the coupled semiconductormodules 300.

The number of semiconductor modules 300 provided in the semiconductordevice 310 is not limited to two. An optional number of semiconductormodules 300 can be coupled with each other in the +x direction and −xdirection in accordance with the rated current of the semiconductordevice 310.

Effects

In the semiconductor module 300 according to the third embodiment, thefirst joining structure 31 includes the male joint, and the secondjoining structure 32 includes the female joint. Assuming that the firstjoining structure 31 and the second joining structure 32 are overlapped,the male joint and the female joint are fitted to each other.

Accordingly, it is possible to join the first joining structure 31 andthe second joining structure 22 of the semiconductor modules 300adjacent to each other by fitting the male joint and the female joint toeach other.

In the semiconductor module 300 according to the third embodiment, themale joint and the female joint are ant-shaped joints.

Accordingly, the lead frames 3 of semiconductor modules 300 adjacent toeach other can be integrated with each other to achieve high strength byusing the ant-shaped joints.

In the semiconductor device 310 according to the third embodiment, thefirst joining structure 31 of one of the semiconductor modules 300adjacent to each other and the second joining structure 32 of the otherof the semiconductor modules 300 adjacent to each other are electricallyjoined with each other by fitting.

The first joining structure 31 and the second joining structure 32 ofthe respective semiconductor modules 300 adjacent to each other can bejoined with each other by fitting without using a joining member such assolder or a screw.

Fourth Embodiment

FIG. 15 is a perspective view of a semiconductor module 400 according toa fourth embodiment. FIG. 16 is a cross-sectional view of thesemiconductor module 400 taken along line D1-D1 in FIG. 15 . Thesemiconductor module 400 has the same configuration as that of thesemiconductor module 100 (FIGS. 1 and 2 ) except for the shapes of afirst joining structure 41 and a second joining structure 42.

The lead frame 3 of the semiconductor module 400 includes the firstjoining structure 41 and the second joining structure 42. The firstjoining structure 41 is disposed on the first side S1 of the lead frame3. The second joining structure 42 is disposed on the second side S2 ofthe lead frame 3. The first joining structure 41 includes a substantialpart 41 a at which the lead frame 3 exists and a void part 41 b at whichthe lead frame 3 does not exist. The second joining structure 42includes a substantial part 42 a at which the lead frame 3 exists, and avoid part 42 b at which the lead frame 3 does not exist.

In addition, the first joining structure 41 includes a plurality ofconcave parts 41 c in the substantial part 41 a. Each concave part 41 cis recessed in a direction perpendicular to the main surface of the leadframe 3 (the z direction). The second joining structure 42 includes aplurality of convex parts 42 c in the substantial part 42 a. Each convexpart 42 c protrudes in the direction perpendicular to the main surfaceof the lead frame 3 (the z direction). The convex part 42 c is thickerat the head than at the base. The concave part 41 c is wider at theinside than the entrance.

Each of the first joining structure 41 and the second joining structure42 has a shape such that one of the first joining structure 41 and thesecond joining structure 42 complements at least part of the void part41 b or 42 b of the other assuming that the first joining structure 41and the second joining structure 42 are overlapped. In other words, inFIG. 16 , assuming that the second joining structure 42 is moved inparallel in the x direction and overlapped with the first joiningstructure 41, the substantial part 41 a of the first joining structure41 complements the void part 42 b of the second joining structure 42,and the substantial part 42 a of the second joining structure 42complements the void part 41 b of the first joining structure 41.

In the fourth embodiment, assuming that the second joining structure 42is moved in parallel in the x direction and overlapped with the firstjoining structure 41, the concave part 41 c of the first joiningstructure 41 and the convex part 42 c of the second joining structure 42are fitted to each other.

FIG. 17 is a perspective view of a semiconductor device 410 according tothe fourth embodiment. FIG. 18 is a cross-sectional view of thesemiconductor device 410 taken along line D2-D2 in FIG. 17 . Asillustrated in FIGS. 17 and 18 , the semiconductor device 410 has aconfiguration in which two semiconductor modules 400 are coupled witheach other. For the sake of description, the two semiconductor modules400 are referred to as semiconductor modules 400A and 400B,respectively, for distinction.

As illustrated in FIGS. 17 and 18 , among the semiconductor modules 400Aand 400B adjacent to each other, the first side S1 of the semiconductormodule 400B is disposed facing to the second side S2 of thesemiconductor module 400A. The first joining structure 41 of thesemiconductor module 400B and the second joining structure 42 of thesemiconductor module 400A are electrically joined with each other byfitting.

In other words, the concave part 41 c provided in the first joiningstructure 41 of the semiconductor module 400B and the convex part 42 cprovided in the second joining structure 42 of the semiconductor module400A are fitted to each other. The convex part 42 c and the concave part41 c are fitted to each other by pressing the concave part 41 c of thesemiconductor module 400B in the -z direction toward the convex part 42c of the semiconductor module 400A.

As illustrated in FIGS. 17 and 18 , the semiconductor elements 1 can beconnected in parallel with each other by electrically joining the leadframes 3 of the semiconductor modules 400A and 400B with each other.Accordingly, the rated current value of the semiconductor device 410 canbe changed in accordance with the number of the coupled semiconductormodules 400.

The number of semiconductor modules 400 provided in the semiconductordevice 410 is not limited to two. An optional number of semiconductormodules 400 can be coupled with each other in the +x direction and −xdirection in accordance with the rated current of the semiconductordevice 410.

Effects

In the semiconductor module 400 according to the fourth embodiment, thefirst joining structure 41 includes the concave part 41 c recessed inthe direction perpendicular to the main surface of the lead frame 3, andthe second joining structure 42 includes the convex part 42 c protrudingin the direction perpendicular to the main surface of the lead frame 3.Assuming that the first joining structure 41 and the second joiningstructure 42 are overlapped, the concave part 41 c and the convex part42 c are fitted to each other.

Accordingly, the first joining structure 41 of one of the semiconductormodules 400 and the second joining structure 42 of the othersemiconductor module 400 adjacent thereto can be joined with each otherby fitting the concave part 41 c and the convex part 42 c.

In the semiconductor device 410 according to the fourth embodiment, thefirst joining structure 41 of one of the semiconductor modules 400adjacent to each other and the second joining structure 42 of the otherof the semiconductor modules 400 adjacent to each other are electricallyjoined with each other by fitting.

The first joining structure 41 and the second joining structure 42 ofthe respective semiconductor modules 400 adjacent to each other can bejoined with each other by fitting without using a joining member such assolder and a screw.

Fifth Embodiment

FIG. 19 is a perspective view of a semiconductor module 500 according toa fifth embodiment. FIG. 20 is a cross-sectional view of thesemiconductor module 500 taken along line E-E in FIG. 19 . Thesemiconductor module 500 further includes the insulating member 4 inaddition to the configuration of the semiconductor module 100 (refer toFIGS. 1 and 2 ).

The insulating member 4 is flat. The insulating member 4 is made of anorganic insulating material or a ceramic insulating material. Theinsulating member 4 is joined with a surface of the lead frame 3opposite to the surface joined with the semiconductor element 1.

Effects

The semiconductor module 500 according to the fifth embodiment furtherincludes the insulating member 4, and the insulating member 4 isdisposed on the surface of the lead frame 3 opposite to the surfacejoined with the semiconductor element 1.

Accordingly, since the insulating member 4 is disposed on the surface ofthe lead frame 3 opposite to the surface joined with the semiconductorelement 1, the cooler or the like can be insulated from thesemiconductor element 1 and the lead frame 3, for example.

Modification of Fifth Embodiment

FIG. 21 is a perspective view of a semiconductor module 501 according toa modification of the fifth embodiment. FIG. 22 is a cross-sectionalview of the semiconductor module 501 taken along line F-F of FIG. 21 .The semiconductor module 501 further includes the cooler 5 in additionto the configuration of the semiconductor module 500 (refer to FIGS. 19and 20 ).

The cooler 5 is joined with a surface of the insulating member 4opposite to a surface on which the lead frame 3 is disposed. The cooler5 is formed of a material such as copper, which has excellent thermalconduction. The cooler 5 includes a base plate 5 a and a cooling fin 5b.

Effects

The semiconductor module 501 according to the modification of the fifthembodiment further includes the cooler 5, and the cooler 5 is joinedwith the surface of the insulating member 4 opposite to the surface onwhich the lead frame 3 is disposed.

Accordingly, since the cooler 5 is additionally provided, thesemiconductor element 1 and the lead frame 3 can be cooled through theinsulating member 4.

S ixth Embodiment

FIG. 23 is a perspective view of a semiconductor module 600 according toa sixth embodiment. The semiconductor module 600 further includes theelectrode terminal 6 in addition to the configuration of thesemiconductor module 100 (refer to FIGS. 1 and 2 ). The electrodeterminal 6 is electrically joined with the lead frame 3. Accordingly,the electrode terminal 6 is connected with the main electrode of thesemiconductor element 1 through the lead frame 3. The electrode terminal6 is used for electrical connection with the outside of thesemiconductor module 600.

The electrode terminal 6 is formed of, for example, the same material asthat of the lead frame 3. The shape of the electrode terminal 6 is notlimited to the shape illustrated in FIG. 23 . The plurality of electrodeterminals 6 may be joined with the lead frame 3.

Effects

The semiconductor module 600 according to the sixth embodiment furtherincludes the electrode terminal 6, and the electrode terminal 6 iselectrically joined with the lead frame 3. Accordingly, thesemiconductor module 600 can be electrically connected with the outsidethrough the electrode terminal 6.

Modification of Sixth Embodiment

FIG. 24 is a perspective view of a semiconductor module 601 according toa modification of the sixth embodiment. The semiconductor module 601includes a hole 6 a at a leading end of an electrode terminal 6. Theother configurations are the same as those of the semiconductor module600 (FIG. 23 ).

The hole 6 a provided at the leading end of the electrode terminal 6 isused for connection with an external wire. For example, a female screwis formed inside the hole 6 a, and can be screwed with the externalwire.

Effects

In the semiconductor module 601 according to the modification of thesixth embodiment, the electrode terminal 6 includes the hole 6 a forexternal wire connection at the leading end. Accordingly, the electrodeterminal 6 can be easily connected with an external wire by, forexample, screwing to the hole 6 a.

Seventh Embodiment

FIG. 25 is a perspective view of a semiconductor module 700 according toa modification of a seventh embodiment. FIG. 26 is a cross-sectionalview of the semiconductor module 700 taken along line G-G in FIG. 25 .The semiconductor module 700 further includes a heat pipe in addition tothe configuration of the semiconductor module 100 (refer to FIGS. 1 and2 ).

The heat pipe is incorporated in the lead frame 3 in the semiconductormodule 700. Specifically, the lead frame 3 is provided with a cavity 7,and differential liquid is sealed in the cavity 7. As illustrated inFIGS. 25 and 26 , the heat pipe incorporated in the lead frame 3 may beextended to the inside of the electrode terminal 6.

Effects

In semiconductor module 700 according to the seventh embodiment, theheat pipe is incorporated in the lead frame 3. Since the heat pipe isincorporated in the lead frame 3, the thermal conduction efficiency ofthe lead frame 3 can be improved.

Modification of Seventh Embodiment

FIG. 27 is a perspective view of a semiconductor module 701 according toa modification of the seventh embodiment. In the semiconductor module701, an insulating member 8 is disposed on an upper surface of theleading end of the electrode terminal 6. The other configurations arethe same as those of the semiconductor module 700 (FIGS. 25 and 26 ).

Since the insulating member 8 is disposed on the top surface of theleading end of the electrode terminal 6, the electrode terminal 6 can becooled by the cooler or the like while insulation from the electrodeterminal 6 is maintained. The position at which the insulating member 8is disposed is not limited to the electrode terminal 6. The insulatingmember 8 may be disposed at an optional position on the lead frame 3.

Effects

In the semiconductor module 701 according to the modification of theseventh embodiment, the heat pipe is incorporated from the lead frame 3to the electrode terminal 6, and the insulating member 8 is disposed onthe electrode terminal 6.

Accordingly, since the insulating member 8 is disposed on the electrodeterminal 6, the electrode terminal 6 can be cooled with the cooler orthe like while insulation from the electrode terminal 6 is maintained.

Eighth Embodiment

FIG. 28 is a perspective view of a semiconductor device 800 according toan eighth embodiment. FIG. 29 is a perspective view of an inside of thesemiconductor device 800 in a state in which the sealing resin 15 of thesemiconductor device 800 is removed.

As illustrated in FIG. 29 , the semiconductor device 800 includes twosemiconductor modules 100 coupled with each other. The lead frames 3 ofthe semiconductor modules 100 are each joined with the electrodeterminal 6. The main electrode on the upper surface of the semiconductorelement 1 provided in each semiconductor module 100 is joined with anelectrode terminal 9. The control electrode of the semiconductor element1 included in each semiconductor module 100 is connected with a controlterminal 13 through a wire 14. The insulating member 4 is disposed onthe surface of the lead frame 3 of each semiconductor module 100opposite to the surface on which the semiconductor element 1 is mounted.Further, as illustrated in FIG. 28 , in each semiconductor module 100,the surface of the lead frame 3 on which the semiconductor element 1 ismounted and the semiconductor element 1 are sealed by the sealing resin15.

In the eighth embodiment, the semiconductor device 800 includes the twosemiconductor modules 100 coupled with each other. However, the numberof the semiconductor modules is not limited to two. Furthermore, insteadof the semiconductor modules 100, a plurality of semiconductor modulesof any one of the semiconductor modules 200, 300, 400, 500, 600, and 700may be coupled with each other.

Effects

In each of the plurality of semiconductor modules 100 of thesemiconductor device 800 according to the eighth embodiment, at leastthe surface of the lead frame 3 on which the semiconductor element 1 ismounted and the semiconductor element 1 are sealed by resin. When theplurality of semiconductor modules 100 coupled with each other is sealedby resin, the coupling between the plurality of semiconductor modules100 is enhanced, and the plurality of semiconductor modules 100 can beprotected from the external environment.

In each embodiment described above, the semiconductor element 1 maycontain a wide-bandgap semiconductor. The wide-bandgap semiconductor is,for example, SiC, GaN, or diamond. When the semiconductor element isformed of such a wide-bandgap semiconductor, a large current can beswitched at high temperature even when a plurality of semiconductormodules is coupled with each other to set a large rated current.

The present invention is described above in detail, but the abovedescription is exemplary in any aspect, and the present invention is notlimited thereto. It is therefore understood that numerous modificationsand variations can be devised without departing from the scope of thepresent invention.

EXPLANATION OF REFERENCE SIGNS

1: semiconductor element

2, 10: solder

3: lead frame

4, 8: insulating member

5: cooler

6, 9: electrode terminal

6 a: hole

7: cavity

7 a: differential liquid

13: control terminal

14: wire

15: sealing resin

20: screw

11, 21, 31, 41: first joining structure

12, 22, 32, 42: second joining structure

11 a, 12 a, 21 a, 22 a, 31 a, 32 a, 41 a, 42 a: substantial part

11 b, 12 b, 21 b, 22 b, 31 b, 32 b, 41 b, 42 b: void part

21 c: through-hole

22 c: hole

41 c: concave part

42 c: convex part

S1: first side

S2: second side

100, 101, 200, 300, 400, 500, 600, 700: semiconductor module

110, 210, 310, 410, 800: semiconductor device

The invention claimed is:
 1. A semiconductor module comprising: a leadframe including an upper surface and a lower surface; and asemiconductor element joined with the upper surface of the lead frame,wherein the lead frame includes a first joining structure, and a secondjoining structure, the first joining structure is disposed on a firstside of the lead frame, the second joining structure is disposed on asecond side of the lead frame facing to the first side, the firstjoining structure includes a void part as a part at which the lead framedoes not exist, and a male joint, the second joining structure includesa void part as a part at which the lead frame does not exist, and afemale joint, each of the first joining structure and the second joiningstructure being positioned entirely between a first plane defined by theupper surface to which the semiconductor element is joined, and a secondplane defined by the lower surface, and each of the first joiningstructure and the second joining structure has a shape such that one ofthe first joining structure and the second joining structure complementsat least part of the void part of the other, and the male joint and thefemale joint complement each other.
 2. A semiconductor modulecomprising: a lead frame; and a semiconductor element joined with thelead frame, wherein the lead frame includes a first joining structure,and a second joining structure, the first joining structure is disposedon a first side of the lead frame, the second joining structure isdisposed on a second side of the lead frame facing to the first side,the first joining structure includes a void part as a part at which thelead frame does not exist, and a male joint, the second joiningstructure includes a void part as a part at which the lead frame doesnot exist, and a female joint, each of the first joining structure andthe second joining structure has a shape such that one of the firstjoining structure and the second joining structure complements at leastpart of the void part of the other, and the male joint and the femalejoint complement each other, and the male joint and the female joint areant-shaped joints.